1. Field of the Invention
The present invention relates to a touch sensor and, more specifically, to conductive element patterns on a touch sensor and methods of determining touch locations with such conductive element patterns.
2. Description of the Related Arts
Modern electronic devices often have touch sensors to receive input data. There are a variety of types of touch sensor applications, such as touch sensors, digitizers, touch buttons, touch switches, touch scroll bars, and the like. Touch sensors have a variety of types, such as resistive type, capacitive type, and electro-magnetic type. A capacitive touch sensor is coated with a conductive material, typically Indium Tin Oxide (ITO) or copper, which conducts continuous electrical current across a sensor. The sensor exhibits a precisely controlled field of stored charge in both the horizontal and vertical axes of a display to achieve capacitance. The human body is also an electrical device which has stored charge and therefore also exhibits capacitance. When the sensor's normal capacitance field (its reference state) is altered by another capacitance field, e.g., by the touch with someone's finger, capacitive type touch sensors measure the resultant distortion in the characteristics of the reference field and send the information about the touch event to the touch sensor controller for mathematical processing. There are a variety of types of capacitive touch sensor controllers, including Sigma-Delta modulators (also known as capacitance-to-digital converters—CDCs-), charge transfer type capacitive touch sensor controllers, and relaxation oscillator type capacitive touch sensor controllers.
Conventional touch sensors typically require multiple layers of ITO to detect multiple touches on the touch sensor. Some conventional touch sensors may use a single ITO layer, but they are not capable of determining the location of multiple simultaneous touches in more than a single direction due to the way the single ITO layer is disposed on the touch sensor.
Therefore, there is a need for touch sensors that more accurately determine the position of touches on a touch-sensitive sensor Likewise, there is a need for touch sensor controllers that are capable of determining the position of a plurality of simultaneous touches along the two dimensions of a touch-sensitive sensor.